The present invention relates to baseball and softball bats. More particularly, the present invention relates to a metal bat having a layered, reinforced barrel.
Baseball and softball are very popular sports in the United States, Mexico, Cuba, Japan and elsewhere. Due to the competitive nature of the sports, the players are constantly seeking ways of improving their performance. An important aspect of baseball and softball is the ability to effectively hit the ball. Aluminum (metal) bats are allowed in baseball amateur play from Little League to College levels. Metal bats are also typically used in slow and fast pitch softball. Such bats are advantageous over wood bats in that they do not break and splinter like wood bats and thus can be repeatedly used with consequent cost savings. Metal bats also have a larger optimal hitting area or power zone (commonly referred to as the xe2x80x9csweet spotxe2x80x9d) than wood bats. Furthermore, the ball comes off a metal bat faster than a wood bat resulting in longer hits.
However, metal bats have certain disadvantages. As opposed to the traditional sound heard when a wood bat contacts the ball, metal bats emit an undesirable high-pitched metallic sound. Metal bats also vibrate upon impact and may send painful vibrations into the hands and arms of the batter if the ball is not hit within the power zone of the bat. Metal bats, particularly aluminum bats, may also dent or otherwise deform due to forceful impacts with the ball.
Various attempts have been made to overcome the problems associated with metal bats. Some attempts have been to coat or wrap the exterior of the metal bat with materials such as carbon reinforcing fibers to enhance batting performance. These externally wrapped bats have been found to be aesthetically unpleasant and lacking in significant improvement. Other attempts have been made to insert internal layers or compartments within the metal bat to improve performance. Such designs include utilizing multiple-layered graphite inserts to provide durability and flexibility to the bat, tubular coiled spring steel inserts to improve the spring-board effect when the ball contacts the bat, and pressurized air chambers within the bat. While providing benefits, these designs also have drawbacks. Some designs are very expensive to manufacture and are prone to structural failure. The composite sheaths break down over time and the bats are subject to premature longitudinal cracks in the barrel of the bat. In many of the newly designed metal bats, the reinforcement is focused around the optimal hitting area or center of the hitting area of the bat and do not run the length of the barrel of the bat.
Accordingly, there is a need for a reinforced metal bat which enhances the performance of the bat and overcomes the disadvantages previously experienced with metal bats. The present invention fulfills these needs and provides other related advantages.
The present invention resides in a reinforced-layer metal composite bat which has a larger hitting zone, produces a xe2x80x9cwoodxe2x80x9d audible sound upon impact, and which reduces vibration when the bat contacts a ball. The bat generally comprises a metal outer shell having a handle, a barrel, and an intermediate tapered section interconnecting the barrel and handle. A composite fiber shell is positioned within the barrel of the outer shell plus a section of 1.50 to 2.5 inches of the tapered section. A metal inner shell is positioned within the composite fiber shell and fixed to the composite fiber shell to form an effective hitting area in the barrel that produces a desirable xe2x80x9cwoodxe2x80x9d audible sound upon impact.
The outer and inner metal shells are typically comprised of an aluminum alloy. The barrel of the outer shell preferably has a thickness exceeding the thickness of the inner shell. First and second opposing open ends of the inner and composite shells are covered with elastomeric caps to dampen vibrations and enhance the desired audible sound upon impact. Preferably, the inner and composite shells are of substantially the same length and extend substantially the length of the barrel of the outer shell. A high impact-resistant resin layer may be interposed between the composite shell and the barrel of the outer shell, or the composite shell can be adhered to the barrel of the outer shell by means of an adhesive.
The method for manufacturing the bat comprises first providing a metal outer shell having a handle, a barrel and an intermediate tapered section interconnecting the barrel and handle. A middle inner shell is also provided. A composite fiber shell is fixed to an exterior surface of the inner shell by laminating composite fibers over the exterior surface of the inner shell. Open ends of the composite fiber and inner shells are closed with elastomeric caps. The composite fiber shell and inner shell are placed within the barrel of the outer shell. A resin may be placed between the inner surface of the barrel and the composite fiber shell, or the outer surface of the composite fiber shell is adhered to the inner surface of the barrel.
The resulting reinforced-layer metal composite bat has a relatively large hitting zone, or xe2x80x9csweat spotxe2x80x9d due to the combination of the composite layers. Use of the resin enhances a trampoline effect when the bat strikes a ball. The elastomeric caps dampen vibrations that tend to sting the hitter""s hands when the bat contacts a ball. Moreover, the overall combination of the composite material sandwiched between two layers of metal shell, as well as the elastomeric caps, produce a xe2x80x9cwood-soundxe2x80x9d effect instead of a typical high-pitched metallic sound common with traditional metal bats.
Other features and advantages of the present invention will become apparent from the following more detailed description, taken in conjunction with the accompanying drawings which illustrate, by way of example, the principles of the invention.